The invention relates to a support installation for large cylindrical load units, particularly large tubes. Specifically, the installation permits the rotation and axial displacement of cylindrical load units and is equipped with rolls arranged on two rotating axles parallel to the axis of the load units. The axles are spaced an axial distance from each other, which distance is less than the diameter of the load units. At least one of the axles is capable of being driven.
The invention originated from a problem arising during the testing of large tubes, wherein the tubes, for the purpose of testing their welded joints, must be both rotated and moved forward in the axial direction. Load support devices will crowned rolls are known for this application; their axles are essentially parallel to the axis of the large tubes, and the latter may therefore be rollingly displaced with rotation on these rolls. In order to obtain a transporting effect in the longitudinal direction, the crowned rolls may be set at a slight angle with respect to the axis of the large tubes. This results in a reeling effect and thus advances the tubes.
The disadvantage of this prior art device consists of the fact that the angle setting device for the entirety of the rolls requires a considerable structural effort, and the installation is therefore expensive. Further, the longitudinal transport of the tubes takes place not by pure rotation, but it involves friction between the rolls and the surface of the tubes which may result in the marking of the surface of the tubes. In the situation where the tubes have a poor surface quality, e.g. those carrying scale on their surface, this condition is immaterial. However, on tubes with higher surface qualities, for example smooth tubes of corrosion resistant steels, such markings are extremely undesirable.